This invention relates in general to power take-offs for selectively providing rotational energy from a source of rotational energy to a rotatably driven accessory. In particular, this invention relates to an improved structure for such a power take-off wherein an input mechanism and a clutch assembly of the power take-off are provided in separate housings that are spaced apart from one another. This invention also relates to a rotatable shaft that connects the input mechanism of the power take-off to the clutch mechanism, wherein the shaft has a passageway for supplying pressurized fluid from the input mechanism to the clutch mechanism.
A power take-off is a well known mechanical device that is often used in conjunction with a source of rotational energy, such as a vehicle engine or transmission, to provide rotational energy to a rotatably driven accessory. For example, power take-offs are commonly used in industrial and agricultural vehicles to provide rotational energy to hydraulic pumps that, in turn, operate hydraulically driven accessories such as plows, trash compactors, lifting mechanisms, winches, and the like. The power take-off provides a simple, inexpensive, and convenient means for supplying rotational energy from the source of rotational energy to the rotatably driven accessory.
A typical power take-off includes an input mechanism and an output mechanism. The input mechanism of the power take-off is adapted to be connected to the source of rotational energy so as rotatably driven whenever the source of rotational energy is operated. The output mechanism of the power take-off is adapted to be connected to the rotatably driven accessory. In some instances, the input mechanism of the power take-off is directly connected to the output mechanism such that the rotatably driven accessory is always rotatably driven whenever the source of rotational energy is operated. In other instances, a clutch assembly is provided between the input mechanism and the output mechanism such that the rotatably driven accessory is selectively driven only when the source of rotational energy is operated and the clutch assembly is engaged.
In both instances, the power take-off is usually mounted directly on the source of rotational energy (such as a housing of a transmission) and the rotatably driven accessory is, in turn, mounted directly on the power take-off. However, if the rotatably driven accessory is relatively large or heavy, it may be relatively difficult to mount the rotatably driven accessory directly on the power take-off. To address this, it is known to provide a rotatable shaft that extends between the power take-off and the rotatably driven accessory. This rotatable shaft allows the rotatably driven accessory to be positioned at a location that is remote from the power take-off, thereby facilitating more convenient installation or service.
Although a rotatably driven accessory that is remotely mounted from the power take-off has functioned satisfactorily in many circumstances, it has been found that the power take-off itself may, in some instances, be so relatively large or heavy as to make it relatively difficult to mount the power take-off on the source of rotational energy. Thus, it would be desirable to provide an improved structure for a power take-off that would facilitate the installation of the power take-off on the source of rotational energy in these circumstances.